It appears Biostar has switched from using Phoenix Award BIOS to American Megatrends. I can't say I welcome this change, as I am far more used to overclocking with Award over the last several years and many of the AMI screens and options were unfamiliar to me. It just takes a while playing around with the various settings however to learn what each does. The first two screens, Main and Advanced, certainly seem simple enough anyway.
The CPU Configuration is more of an informational display, however there are a few options that can be changed, the most notable of which is the PowerNow setting. With this enabled, the system will reduce the CPU multiplier to conserve power when there is low utilization. For overclocking, you will more than likely want this disabled. The Hardware Health section can be helpful by configuring a maximum temperature ceiling for shutdown, so you don't risk overheating your processor. The rest of the voltage and temp info on this page is for display only.
PCIPnP and Boot screens are basic BIOS options available in some form or another in nearly every machine out there. The Chipset page gives you all of the options having to do with the onboard graphics. Here we see the setting to enable Hybrid SLI as well as options for the iGPU. The 16x PCIe slot can also be set to support either version 1.0 or 2.0 mode.
The T-Series screen is really where things begin to get interesting. There are two versions of that page shown above. The first one on the left is the 03/04 BIOS release that shows the CPU Multi option grayed out. The picture in the center shows the 05/29 version which opens up a whole new sub-menu for Custom P-States, shown on the right. I was able to perform some amount of overclocking with the old BIOS just by increasing the base frequency from 200 to 231, however with no separate multiplier and northbridge control there was a limit to how far the chip would go. The new version gives you the individual CPU and NB multipliers and dividers needed. With Phenom, the core frequency can be adjusted separately from the internal northbridge frequency, and there are now multipliers for each and even dividers for the multipliers. There could be an entire article devoted to Phenom overclocking, but for sake of brevity, I won't get into that in this review.
The Over-Voltage sub-menu gives you complete control of CPU, NB, Memory, Chipset and HT voltage increases. The settings for the CPU Core and CPU Northbridge are individually adjustable, although both have the same range up to +0.30v over stock in 0.02v increments. Memory voltage can be increased from the default 1.8v, initially in 0.05v increments, and changing to 0.10v once over 2.0v, up to a maximum of 3.3v. That is more than enough volts to void the warranty of every memory manufacturer on the planet. Likewise the Chipset and HyperTransport voltages can also be increased well over stock settings, more than will ever likely be needed.
I found the DRAM Timing sub-menu to be a little confusing. The timing values that I set manually were not the ones that appeared in the current display, even after a reboot. And they also didn't quite jive with timings reported by CPUz later when booted into the OS. I tried playing around with the Memory Configuration options but couldn't seem to get these to ever match up right. I was also a bit puzzled by the apparent ability to set different timing values for each channel bank. I suppose this may have some use, but I would think for stability reasons, you would not want to run disparate timings. Finally it should be noted that although the BIOS supports DDR2-1066, the timings available when configured for 533 are different from those at 400 or below. For example, CAS5 is the lowest value on the option list when set to 533, although changing this to 400 opens up CAS3 and 4. If you're using memory that will run the lower timings at the higher speeds, you may want to configure it as 400 and overclock to 533 or more by increasing the base reference frequency.
The last two BIOS options I wanted to point out are the Integrated Memory Test and CMOS Backup. As in previous generations, this latest TForce includes a copy of MemTest built into the BIOS that can be used to test the memory without the need for separate boot media. The CMOS Backup can be used to save and later reload all of your custom settings so you don't have to manually set them in the event the BIOS is cleared. When overclocking, I highly recommend making use of this feature.
In previous Award BIOS boards, there was a Flash utility built into the BIOS, however Biostar has not left us out in the dark. The included software CD comes with a utility for upgrading the BIOS from within the OS. Although I usually prefer to do this from a clean boot, I did try the utility and it works flawlessly. I was able to use this feature to flash the new 05/29 BIOS from within Windows. The only complaint I have is that when the BIOS is flashed in this way, it wipes out any custom settings you may have set, including your saved backups, and so you will have to manually configure everything again after a reboot.
Let's try some overclocking.